Final answer:
Car b is going approximately 111.56 kilometers per hour.
Step-by-step explanation:
To find out how fast car b is going in kilometers per hour, we first need to determine the speed of car a. Given that car a is going 60 miles per hour, we can convert this speed to kilometers per hour. Since 1 mile is equal to 1.60934 kilometers, we can multiply 60 by 1.60934 to get the speed of car a in kilometers per hour, which is approximately 96.56 km/h.
To determine the speed of car b which is 15 miles per hour faster than car a, we add 15 to the speed of car a in kilometers per hour. So, the speed of car b is approximately 96.56 + 15 = 111.56 km/h.